Improvised Suppressors When SHTF: Keeping Quiet When It Counts

By Travis Noonan
October 1, 2019 06:02

Editor’s Note: Keeping quiet when SHTF and not giving away your position to bloodthirsty looters can prove vital. And a silencer is the tool you need to do it. That being said, the Askaprepper team must warn everybody reading this article that in times of peace making or owning a silencer is mostly illegal. And it carries a hefty penalty and possible jail time.

Investing in a good firearm suppressor will give any prepper a tactical advantage. The problem with suppressors is the cost and legal stuff – rather, the National Firearms Act (NFA) of 1934. The NFA made it incredibly difficult to buy a suppressor. You must get fingerprints taken, meet with your local sheriff, submit to an enhanced background check, fill out loads of paperwork, pay a $200 tax stamp, and wait up to one year just to get the green light to buy one.

None of that’ll be possible when disaster strikes, and most of us preppers and gun owners won’t bother with this legalese, anyway. But that doesn’t mean you can’t enjoy the benefits of a suppressor when it really counts. This guide’s going to show you the top improved suppressors, so you can keep quiet when SHTF.

Quick legal disclaimer: We love to inform, but we’re not lawyers. Nothing in this guide should be taken as legal advice. Any information in this guide is for educational purposes only. You should consult with an attorney before buying or building a firearm suppressor.

How Suppressors Really Work

We think it’s important to first talk about how suppressors actually work. First, even using one of the best suppressors on the market isn’t going to turn your supersonic rifle into a whisper-quiet shooter like James Bond’s Walther.

Suppressors work by trapping all the supersonic hot gasses exiting the muzzle of the barrel as a round is fired. The suppressor slows down the speed of the gas and allows it to expand more slowly, before exiting the muzzle and suppressor. This creates a lot of heat but it also reduces the sound of the reported gunshot.

The average firearm suppressor reduces the sound of gunfire by about 30 decibels. Independent tests say that’s roughly the equivalent to putting on a good pair of ear protection while firing.

If you’re shooting supersonic rounds (like a 5.56 or .308 rifle round), you’re still going to get that telltale crack when the bullet breaks the sound barrier. Only by firing subsonic ammo (usually handgun ammo) will you get your gun firing quiet enough that someone in the next room might not hear it.

Using a quality, down pillow will reduce the reported gunfire enough that ear protection may not be required – just like a real suppressor. The only drawbacks to this improved can are that it’s usually one-time-use and it requires you to shove the barrel into the pillow. That obviously means accuracy goes out the window. But in a close-quarters pinch, the pillow suppressor works wonderfully.

#2. The Oil Filter Adapter

Commercial suppressors are made from aluminum, they have threaded fittings, and they’re filled with paper and metal media. Oil filters are amazing improved suppressors. A used oil filter will work even better!

To make this suppressor work, you just need to buy the right threaded adaptor. All you need to do is figure out the threads on your muzzle (usually ½” x 28 to ¾” x 16), and the threads on the filter in question. Many of these adaptors can be bought online, and they’re only a few bucks.

An oil filter suppressor needs no special modification or extra work – just thread it on and send some rounds downrange. Most oil filters are good for at least a few rounds before the media inside goes to waste.

Accuracy won’t suffer with one of these bad boys, either. And if SHTF happened, finding more “suppressors” means lifting a few filters off some abandoned vehicles. Simple!

#3. The Solvent Trap Kit

Technically, this “improvised suppressor” approaches a real suppressor in form and function so much that it really should be called one. But officially, the solvent trap kit is a firearm accessory that is designed – at least, makers claim they’re designed – to trap the cleaning chemicals in your barrel while you swab the bore.

Solvent trap kits are long, suppressor-sized tubes with threaded fittings already sized up for your muzzle. Inside, these tubes also have “solvent filters”. Really, these filters are designed and built to look and perform exactly like the baffles in a real suppressor.

To legally get away with selling these kits, most solvent trap makers cap one end of the tube, so it’s technically not functional. Inside, even the “filter” baffles are drilled out for the appropriate caliber. All you need to do is center and drill a small hole in the end cap, and voila. You’ve got a real suppressor that’ll last for hundreds of rounds. Basically, the solvent trap kit is to the suppressor what the 80 percent lower receiver is to the AR-15 market: A “blank” that can’t be legally defined because it’s not complete.

Solvent trap kits can be purchased with everything you need (tube, baffles, end caps, and all but one hole drilled), but you can also piece together your own kit for fun. Most shooters stick with Wix filters, either the 4003 or the 24744, which can be bought on Amazon. With the tube purchased, one simply needs to find the right “filter” (baffle setup) and threaded end caps for the tube.

Make It Legal

Many shooters choose to build their own, official suppressors using solvent trap kits because they’re so well-designed. These kits are perfect for preppers because you only need to drill that end cap to make it functional. Doing so does make your kit a suppressor in the eyes of the law. If you do drill the end cap and use your kit as a suppressor, you need to first file for an NFA tax stamp and pay the $200 fee.

If you’re prepping and SHTF, however, you don’t need to drill that end cap until the time comes. Read between the lines here.

(Dis)honorable Mention: The Potato

Yes, you’ve probably heard of the famed “potato suppressor”. We want to stress something: Shoving a gun barrel into random objects is not safe. The improvised suppressors we discussed here work safely because they’re not at risk of, well, exploding.

Pillows, oil filters, and solvent kits have cavities and empty space that allow those hot gasses from the muzzle to expand safely. A potato is a solid object and trying to use one as a suppressor will result in said potato exploding.

You could also damage your weapon or seriously injure yourself by shoving the barrel into a potato and pulling the trigger. A plugged up obstruction at the muzzle could cause the barrel, chamber, or receiver to crack or explode.

It will. However the gas that comes out the muzzle right behind it will shred the inside of the filter and might split the casing before, or as, the bullet punches that hole. Anyway, an oil filter is only going to be good for half a dozen rounds at best. Do you really want to waste one of them punching a hole? Because it’s not going to be very accurate on its way downrange. I’d say it’s worth the time to drill a hole.

When I was on peacekeeping duty in Croatia, during the early 90’s, we tested the empty pop bottle idea. IT DON’T WORK. In fact, the empty pop bottle suppressor didn’t work until we filled it with material for baffling.

Glad to see the legal disclaimer, and mention of the NFA tax stamp process.
If it is curiosity, find a person with a legal suppressor and go to a safe range and shoot with it. You may find yourself unimpressed. If for some reason you wish to pursue getting or building one, cough up the 2 bills and rest easier…..

While I have no first hand experience with a potato, I do know what snow will do to a barrel when a round is fire. My very first .22 has a ringed barrel thanks to one of my brothers getting snow in it and firing it with snow filling about 4 inches of the barrel. Neither of them will ‘fess up.Surprisingly, it had no effect on the rifle’s accuracy. It is still a tack driver. That’s was the biggest surprise of all.

I think shooting a potato off the end of your muzzle, especially if it is anything other than a .22 will leave you amazed and chagrin as your buddy who was 50 yards behind you picks scraps of barrel out of your face. You may be lucky and have the potato fly off without damaging your firearm but I don’t trust Lady Luck.

Anybody have an idea on sound levels ( in DB ) for various guns / ammo without a suppressor ? Article claims a 30 Db reduction for a suppressor. My question, what are you starting at. I am going to guess 100 – 120 DB.

The best hearing protection I can find is 33 db n.r.r. A 30 db is about what most hearing protection is rated at. Even with a 30 db rating, the noise is still damaging to your hearing over many years.

While it is too late to help my hearing now, I always wear two sets of hearing protection, foam plugs in the ears and mickey mouse type hearing protectors. I like the electronic ear muffs because if someone is speaking I can turn the sound on and hear what the are saying and still have some protection if someone touches off a loud firearm.

The local range I frequent is terrible for hearing protection. It has a concrete pad that the shooters stand on for shooting and a corrugated metal roof. We used to have a plywood roof with egg cartons stapled to the plywood. That attenuated the sound somewhat. Alas, after 50 years the plywood died a natural death. The egg cartons departed about 20 years ago. The new tin roof may last longer, but I am afraid by that time all the club member will be stone deaf.

Some ranges have a gravel or crushed rock mat to stand on. In my opinion that is better construction for a shooting range than a concrete pad. While grass would be better at attenuating the sound, the crushed gravel doesn’t offer the sound reflecting surface that concrete does.

I don’t know which is worse. Shooting without a suppressor or shooting with a suppressor made out of a used oil filter. Even if the oil filter has been drained thoroughly and is theoretically empty of all oil, my experience is that there is always some residual oil trapped in the filter no matter how long it drain — well, maybe twenty years will leave a thoroughly dry filter.,

I can just imagine the blow-back from a used oil filter. You will be easy to identify as the shooter because I think you will look like some cartoon character.

I would ask if anybody has ever tried that, but I don’t want to read any admissions against interest in print on this site.

If you have ever tried that, please don’t say so on this site— or any other site for that matter.

Because the author of the article suggested that a used oil filter might be more effective than a new one. That’s why I was deriding the idea of employing a used oil filter.

“Oil filters are amazing improved suppressors. A used oil filter will work even better!”

“And if SHTF happened, finding more “suppressors” means lifting a few filters off some abandoned vehicles. Simple!”

I think the author meant “improvised suppressors” rather than “improved suppressors” but when folks use the wrong words we are left to guess at their actual meaning. “Improved suppressors” is meaningless in the context of the other verbiage.

The oil filter suppressors have been around for a long time.
The early mentions I have seen claimed that a predrilled hole is not necessary as the first round fired will do that and give a perfectly centered hole. Do not know how this would work with a 5.56 0r 7.62 rifle round. I suspect the volumn of gas might rupture the canister. Generally suppressors are really only effective with sub sonic bullets anyway as someone already mentioned the crack of supersonic projectiles is impossible to muffle in any way. Thus a 45 ACP at 800 FPS is easier to supress than a 22 long rifle at 1350 FPS, although sub sonic target ammo suppresses quite well.

I would be really, really careful about shooting stuff off the end of your barrel. The only thing that I know that can be safely shot off the end of a barrel is a condom. I know that from first hand experience and from the experience of others whose judgment I trust.

As far as shooting a hole in an object that has been fastened to the end of the barrel — well, I don’t have any first hand experience but I would be very reluctant to try that. I will watch you do it while I am behind a barrier a reasonable distance away.

Gun pressures are like gasoline. We are around them a lot and nothing ever happens so we get very casual in how we treat them — until things go BOOM! Then we wonder “wha hoppen?”

In an end of the world scenario, having an ophthalmologist around to extract small pieces of steel from your eyeball is not a likely scenario. You really don’t want me plucking tiny chucks of steel from your eyeball with my fishhook tweezers.

I have used an oil filter on the end of an AR. It works very well for about 100 full power rounds. After that, the internal material didn’t deaden the sound as much as the first. Don’t worry about drilling the hole in the end; the metal is so thin, the first round will make the hole for you. After the 100 rounds, the hole was a bit larger, but not much. The paper internals were pushed to the front and were sucked/pushed through as the rounds were fired. I fired at a target 100 yards or so away and didn’t find accuracy improved/degraded that much. In some registered cans, users have put oil or water into the can as the gasses would heat the fluid and the report would be reduced. This is called a wet test. Using a used oil filter would be problematic as IMHO, would turn the gas into a signature cloud after awhile. How much, don’t know. In a SHTF scenario, I would turn them upside down for about a day, getting rid as much as the oil as I could before mounting on my rifle. As far as how many rounds you could fire before not getting good useage; i.e. obstructed barrel, accuracy loss, smoke signature, etc; again, I don’t know. I think someone had better conduct some testing and post later.

You can purchase aluminum “solvent traps” off the internet for $13.00 and up. They are six-inches in length, have seven baffles and a spacer. They are primarily available with 1/2-28 threads, but other sizes are available. The end cap and all the baffles have a “dimple” in them to center the drill, so a hand drill can be used.

There are adapters available ($49.95) that clamp on your barrel so you won’t have to pay to have a gunsmith thread your barrel.

If you opt for an adapter, use a micrometer to measure the diameter of the very end of your barrel and the diameter of the barrel one-inch from the end of the barrel. When you decide which one you want call the company and give them the dimensions and they will work with you to ensure you get the correct adapter.

An old plastic milk jug filled a little less than half way with water will work too for a few rounds, after putting the water in just tilt the jug and stick the barrel in the opening and let it go bang.

Not really. The only suppressors that will last more than a few rounds are proper ones with steel internal baffles. They’ll last as long as you keep them clean and oiled. The pressure of the muzzle blast will quickly tear up anything else. Insulation, steel wool, paper oil filters – it doesn’t matter. It’ll get ripped to shreds and compacted at the front end. That makes it less effective at slowing down the expanding gas, and it can play hell with your bullet too. Personally I’d recommend you just bite the bullet and get the tax stamp and a real suppressor. If you don’t want to do that a solvent trap is the best idea.

It really annoys me that in “anti-gun” Europe suppressors are easily available. In some countries they’re actually encouraged or even mandatory.